The Australian pop-punk-loving quartet of tousle-haired hunks (whose members don't consider themselves a boy band) will make its debut Sunday on MTV's over-the-top annual celebration. Boy bands have a long history of VMAs hysteria and much-hyped appearances (think 'N Sync and its 2013 reunion rumors). 5SOS rides the release of a hit album and an opening gig on One Direction's stadium tour into its appearance at the Forum in Inglewood, California.

It's not every awards show where the ratio of cowboy hats per head outnumbers, well, everything else. Throw in a lot of boots and big hair and songs referencing various types of automobiles, and we reckon your Honky Tonk Badonkadonk's definitely at the CMA Awards.

"It was just a matter of time. Everybody would ask us, 'When are you guys going to do something?' " Chasez said Monday on On Air with Ryan Seacrest. "First of all, it was the worst-kept secret ever, [but] Justin gave me a buzz and he said, 'Hey man, listen. I'm getting this award and they have given me a pile of time to perform and we started our careers at MTV and I think we should get the band back together."

On a pre-planned birthday trip to Italy, Chris Kirkpatrick surprised his girlfriend of two and a half years, marketing rep Karly Skladany, by proposing – and she said yes!

Though Kirkpatrick, 41, hadn't planned to pop the question, he says he got caught up in the moment.

"We had a hotel room at the Isle of Capri, overlooking the Mediterranean," he says. "It was one of the most beautiful places I've ever been. And it hit me: I wanted to propose to Karly. So I ran to a jewelry store, found the perfect ring and bought it."

"I had a blast on the show the first time," he tells PEOPLE, "so I wanted to do it again."

Fatone competed in season 4, placing second to champ Apolo Anton Ohno, who'll also compete on the upcoming edition of the show, which premieres Sept. 24 on ABC. But this time, Fatone says he knows how to score the elusive mirror-ball trophy.

Still, he insists, "I think when the stars are aligned, the time is right, and all five of us have our heads on straight and know the direction we're going as a band, it'll eventually happen. If not, I know we'll be best friends forever."